The inventive concept relates to image sensors and methods of forming the same.
Image sensors are semiconductor devices that convert an optical image into an electrical signal. The image sensors may be classified into charge coupled device (CCD) type image sensors and a complementary metal oxide semiconductor (CMOS) type image sensors. CIS is short for the CMOS type image sensor. The CIS includes two-dimensionally arranged pixels. Each of the pixels includes a photodiode (PD). The photodiode converts incident light into an electrical signal.